Adjusting mechanism for welding electrode rolls



Jan. 9, 1951 N. D. ABBEY 2,537,503

ADJUSTING MECHANISM FOR WELDING ELEQTRODE ROLLS Filed April 29, 1949 2Shets-Sheet 1 72 21 0 l 23 4 %4 I zz "'l l 27 I! i 13 I l I 16 l '1 5 NH17 A I 1:! 'l

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' ATTYT N D ABBEY ADJUSTING MECHANISM FOR WELDING ELECTRODE ROLLS Jan.9, 1951 Filed April 29, 1949 Patented Jan. 9, 1951 UNITED STATES PATENT,OFFICE ADJUSTING MECHANISM FOR WELDING ELECTRODE ROLLS Nelson D. Abbey,Toledo, Ohio Application April 29, 1949, Serial No. 90,336

1 Claim. 1

This invention relates to tube mills but particularly to machinesemploying rotating welding electrode rolls for welding together theedges of an axial seam-cleft in a cylindrical pipe length formed from aflat ribbon. I

In tube'mills for producing welded seam tubing, the tube isprogressively formed from a flat ribbon by a series of rolls arranged inpairs at spaced intervals. Not infrequently, a distance of fifty feetintervenes b tween the initial flat form of the strip and the tube format the welding station. It is important that these various rolls, aswell as the electrode rolls, be properly aligned to militate "againstbending the tube and thereby imposing undue frictional resistance to theadvancing movement of the tube and obviating the liability of displacingthe ed es of the tube relative to the welding electrode rolls.

From time to time, the position of the welding electrode rolls changesaxially due to the expansion under influence of heat, of the transformer shaft. Even though this change may be slight, it is sufiicient tointerfere with efficient welding and, therefore, must be compensated forone way or another. vSeveral expedients have been resorted to in orderto cope with this problem but they have achieved only pare tial success.

For example, effort has been made to adiust the long series of rolls butmanifestly, this is difiicult, time-consuming, and often results inbending the tube. The latter is particularly evident if thewelder-support rolls alone are adjusted independently of the remainingrolls.

Another expedient has been the dressing of the grooves in the weldingelectrode rolls, but this entails not only shutting down of the entiremm, but also wastes expensive copper of which the electrodes are formed.

A further expedient has involved the axial adjustment of the transformershaft to compensate for .such expansion. This has required theadjustment of the shaft bearing boxes but this has proved to beimpractical because of the relative inaccessibility of the adjustingmechanism and the necessity of carefully and uniformly adjusting theseveral mechanisms. This also required shutting down of the transformerespecially when the adjusting devices are at the front and near theelectrodes because of the danger hazard. With the adjusting devices atthe rear of the machine, the services of two men are required, one toobserve the position of the electrode rolls and the other to effect the,adjustment.

strip which is progressively formed into a From the above, it will beapparent that it is a desideratum to produce a simple and efficientmechanism for axially adjusting the welding electrode rolls during theoperation of the transformer from the front of the tube mill so that oneoperator can make the adjustment readily, conveniently and accuratelyand .from time to time as conditions require. It is an object of thisinvention to produce such mechanism.

For purposes of illustration but not of limitation, an embodiment of theinvention is shown on the accompanying drawings, in which Figure l is afront perspective view of a portion of a tube mill and showingparticularly the adjustable unitary mounting for the transformer weldingelectrode rolls and associated parts;

Figure 2 is a side elevation of the adjustable unitary mounting for thetransformer and welding electrode rolls; parts being broken away to showthe adjusting mechanism for axially shift.- ing the welding electroderolls;

Figure 3 is a sectional view substantially on the line 33 of Figure 2;and

Figure 4 is a fragmentary sectional viewshowing the manner in which thewelding rolls and pressure rolls engage the tube during the weldingoperation.

The illustrated embodiment of the invention comprises a bed or frame Inwhich provides'a platform on which are mounted, on vertical axes, rollsarranged in pairs and spaced from each other. Only a portion of theserolls is shown because the tube is formed from a flat cylinder or tube Tas the strip advances. These rolls which are illustrated are pressure orwelder support rolls. The tube T is formed so that the free edges areuppermost and as shown in Figure 4, are held by pressure rolls l2engaging on opposite sides of the tube. The metal in the region of thespaced edges is fused in response to a pair of electrode rolls l3 whichare contoured to fit the external walls of the tube and rotate as aresult of frictional engagement with the tube as the latter advances, itbeing understood that roll (not shown) are power driven to impartadvancing movement to the tube. The electrode rolls l3 are suitablymounted in a rigid manner upon the outer end of a transformer shaft I4,the transformer being indicated at I5 and being disposed within ahousing 16. It is to be understood that electrical gurrent is deliveredto the transformer IS in any suita l m nner and that current from thetransformer is delivered to the electrode rolls I3 in any suitable orwell-known fashion and since the same forms no part of the presentinvention, detail illustration and description thereof is not considerednecessary.

The housing it is of substantially rectilinear form and in each cornerthereof is an upright column I1 and the lower ends of the columns arerigid with a base I8. The upper ends of the columns 1! are rigidlyconnected to a platform I9 on which is mounted an electric motor 28whose shaft 2! connects through a gear reduction contained within a box22 to horizontal shafting 23. At opposite ends of the shafting '23 areworms contained within casings 2d and each worm meshes with a worm wheel25 operating a screw-threaded shaft 253 which is in threaded engagementwith the upper end of a rod 21, the lower end of which is secured to thehousing I 6. Thus by operating the motor 25) through the connectionsdescribed, the housing I S, the transformer 55 and associated parts maybe raised and lowered along the columns ll, thereby to control thevertical positioning of the electrode rolls I3.

From the above, it will be apparent that the transformer welding rollsand associated structure are mounted as a unit upon the base it. As willhereinafter ap ear, the base i 8 is mounted for translatory shiftingmovement transversely of the bed If: thereby to enable axial adjustmentof the welding rolls I3 thereby to enable expansion of the transformershaft displacing the elec trodes relative to the seam to be welded, tobe readily and accurately compensated for.

Formed on opposite sides of the base it are elongate grooves 28 intowhich project gibs 29 which are secured by bolts 3i! to the bed iii. Inorder that the base 58 move r ctilinearly, a key 3| is disposedcentrally between the base I8 and the bed I6. Fixed to the under side ofthe base I 8 and extending into an elongate slot 32 in the top of thebed IE] is a bracket 33 which is screw-threaded to engage the threadedend portion 34 of a shaft 35. The outer end portion of the shaft 35extends through a beam {it rigid with the bed Iii, anti-friction thrustbearings being disposed on opposite sides of the beams and collars 33integral with the shaft ()n the outer end of the shaft 35 is a squaredend portion 39 which may be engaged by a socketed hub 40 of a hand crankM. An opening 42 in the front of the bed ill affords access to thesquared end.

From the above description, it will be manifest that when it isnecessary to effect axial adjustment of the welding electrode rolls l3,by applying the hand crank M to the squared end 39 of the shaft androtating the screw 34 in one direction or the other, the entire unit maybe shifted transversely of the bed It. This adjustment may be effectedduring the operation of the transformer as well as the tube mill. Sinceonly fine adjustments are ordinarily necessary, the pitch of the threads34 on the shaft 35 accordingly fine. It will be apparent that thisadjustment can be effected from the front of the machine so that theoperator can. watch the position of the welded seam and any deviationfrom the proper location of the seam can quickly and accurately berectified. It will be understood that the vertical adjustment effectedthrough the operation of the electric motor 20 is only made fordifferent diameters of the tube T and ordinarily one setting issufficient for one diameter of the tube. The compensation required isprincipally the axial adjustment of the electrode rolls it caused, asabove pointed out, by the expansion of the metal of the transformer,transformer shaft and associated parts.

Mounted on the front face of the housing I6 is an electrode dressingdevice 43 by means of which each of the electrode rolls I3 may from timeto time be dressed as occasion demands. This structure is well-known tothose skilled in this art, and since it forms no part of the presentinvention, further description is not considered necessary. 7

Itis to be understood that numerous changes in details of construction,arrangement and operation may be effected without departing from thespirit of the invention especially as defined in the appended claim.

What I claim is:

A tube welding machine comprising a support having a front and a rear, aplurality of rolls arranged on said support at spaced intervals andforming an elongate series extending lengthwise of and adjacent to saidfront, a transformer supporting frame arranged on said supportrearwardly of said rolls, a transformer within said frame, a rotatabletransformer shaft rotatably carried by said supporting frame and havinga free end extending forwardly therefrom and lying transversely oversaid roll seriesfa pair of welding electrode rolls deriving current fromsaid transformer, said rolls being mounted on said forwardly extendingtransformer shaft adjacent the free end thereof and being respectivelydimensional and-spaced to engage a tube engaged in said roll series, anelongate guideway extending rearwardly on said support from said rollseries movably mounting said transformer supporting frame on saidsupport, and adjusting means on said support for adjusting saidtransformer supporting frame along said guideway, said adjusting meansbeing disposed in front of the welding electrode rolls whereby to enablethe operator to effect axial adjustment of the rolls while viewing theposition of the electrode rolls with respect to the tube.

NELSON D. ABBEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

